Field of the Invention
This invention pertains to monovalent agents (including Fab fragments and other monovalent NGF binding agents identified infra) having binding specificity to human Nerve Growth Factor (hereinafter “NGF”), and methods of using one or more of said monovalent agents in methods of treating pain in an individual wherein there is no substantial increase in the inflammatory response of the individual following administration of the one or more monovalent agents. These monovalent agents optionally may be modified to extend their circulation half-life such as by the addition of polyethylenes glycol (PEG), or other water soluble polymers and the like)
Description of Related Art
Nerve Growth Factor (NGF) (also known as beta nerve growth factor (Beta-NGF)) is produced as a mature protein of 222 amino acids in length, following cleavage of a 18 amino acid signal peptide. The gene encoding NGF is located on chromosome 1p13.1. A biologically active form of NGF is a secreted protein which homodimerizes and is incorporated into a larger complex. NGF is a member of the neurotrophins (NTs), which are a group of structurally-related proteins further including brain-derived neurotrophic factor (BDNF), NT-3, and NT-4/5. (Wyman et al., Gene Therapy (1999), 6:1648-1660). NTs support the survival of specific types of neurons and neurotransmitter systems, being produced by cells that are targeted by innervating neurons. Id. Basal forebrain, substantia nigra, brain stem, cortex, and spinal cord are nervous system regions having demonstrated responsiveness to NGF. Id.
All NTs bind to a low-affinity receptor identified as p75. (Sarchielli et al., Expert Rev. Neurotherapeutics (2004), 4(1):115-127). NGF selectively binds to, and displays a high affinity for, the high affinity neurotrophin receptor TrkA. Id. It has recently been demonstrated that NGF acts through its low-affinity receptor p75 in a developmentally-regulated signaling pathway necessary for myogenic differentiation and muscle repair in vivo. (Deponti et al., Mol. Biol. Cell (2009), 20:3620-3627).
NGF has also been demonstrated to interact with pain-signalling systems in adult animals, and is responsible for hyperalgesia when administered either locally or systemically in many species. (Sarchielli et al., Expert Rev. Neurotherapeutics (2004), 4(1):115-127). NGF has been shown to induce a pain-like response when infused into the CSF in rats, and has been demonstrated to maintain chronic pain. Furthermore, NGF has been demonstrated to contribute to the development of mechanical allodynia occurring 8-12 hours later, and to the secondary pain response. Id.
Pain may often be addressed through the administration of certain narcotics or non-steroidal anti-inflammatory drugs (NSAIDs). However, the administration of these treatments may occur at the cost of certain negative consequences. NSAIDs have the potential to cause kidney failure, intestinal bleeding, and liver dysfunction. Narcotics have the potential to cause nausea, vomiting, impaired mental functioning, and addiction. Therefore, it is desirable to identify alternative treatments for pain in order to avoid certain of these negative consequences.
NGF is believed to play a role in a multitude of diseases and disorders, including but not limited to pain associated with a broad range of diseases and disorders, such as pain associated with cancers, neuropathic pain, and neurogenic pain. Due to the perceived involvement of NGF in a wide range of pain-related diseases and disorders, there remains a need in the art for compositions and methods useful for preventing or treating diseases and disorders associated with NGF, and particularly those associated with pain. Particularly preferred anti-NGF compositions are those having minimal or minimizing adverse reactions, such as inflammation when administered to the patient. Compositions or methods that reduce or inhibit diseases or disorders associated with NGF, such as pain, are beneficial to the patient in need thereof.